K-space Signal Occupancy of Starlink Signals and Their Applications in Passive Radar Imaging

In this paper, the possibility to exploit Starlink satellites as illuminators of opportunity for passive inverse synthetic aperture radar is investigated. Specifically, the always on beacon signals transmitted by Starlink satellites are considered as a reliable source of illumination. Although these signals are inherently narrow-band, their potential reception over long times (e.g. few minutes), and the corresponding significant variations of the aspect angle to a target during such times, allow the exploitation of beacon signals for Doppler radar tomography, following an approach similar to the one described in [1]. To this end, the slow-time K-space signal occupancy of Starlink beacon signals is derived and it is shown how the K-space can be filled in. The possibility to utilise simultaneously multiple beacon signals originating from multiple Starlink satellites is also investigated.